Solid cosmetic preparations, such as powders, having a high water content are known in the prior art. The basis of some patent applications is the long-known fact that in the presence of a hydrophobic powder, such as a hydrophobic silicon dioxide powder, water can be dispersed into fine droplets and enveloped by the hydrophobic material, thus preventing the droplets from rejoining. A powdery substance having a high water content, known as “dry water”, is formed in this way (Fine Particles series no. 11, Evonik Degussa). Cosmetic formulations based on “dry water” are described in Seifen, Fette, Öle, Wachse (SÖFW), 8 (2003), pages 1-8. These are free-flowing, fine powders, which liquefy when rubbed on the skin. Water-containing, liquefiable powder compositions based on this principle are further disclosed in several patent applications and patents.
U.S. Pat. No. 4,274,883 discloses an aqueous dispersion of a hydrophobic silica consisting of 0.1 to 50 parts of hydrophobic silica, in a given case up to 3 parts of wetting agent and 99.9 to 50 parts of water. It is produced by intensive mixing of hydrophobic silica with water with the known “dry-water-phase” as an intermediate step. In a given case there can additionally be used a wetting agent in which case the “dry-water-phase” does not occur. The dispersion of hydrophobic silicas can be mixed without additional steps or materials with rubber latex.
DE-A-1467023 discloses the use of aqueous solutions comprising cosmetic ingredients instead of pure water for the preparation of dry water.
EP-A-1206928 discloses a water-containing powder composition comprising aqueous gel cores coated with hydrophobic particles.
JP 2000-309505 discloses a cosmetic powder being liquefied by embrocation including 2-20 wt. % of a hydrophobic silica having a specific surface area of at least 60 m2/g and an oil-in-water type emulsion composition.
EP-A-1235554 discloses a cosmetic or pharmaceutical powder-to-liquid composition comprising hydrophobically coated silica particles into which are incorporated water and a water soluble polymer, the composition containing less than 1% oil.
EP-A-1386599 discloses a method for producing dry water composed of an aqueous ingredient coated with a hydrophobic powder to form a powder state capable of liquefying upon embrocation at the time of use, comprising charging a hydrophobic powder and an aqueous ingredient into a hollow container forming a hydrophobic enclosed space in the inside thereof, followed by agitating at a high speed in the hydrophobic hollow container to form fine aqueous droplets, and then allowing the surface of the fine aqueous droplets to be uniformly adsorbed with the hydrophobic powder.
WO 01/85138 A2 discloses an encapsulation system comprising a core of aqueous liquid having at least 5% by weight water therein, and an encapsulant surrounding the core to form stable encapsulated particles, the encapsulant comprising at least one layer of hydrophobic particles in contact with and surrounding the core, the core and hydrophobic particles providing an encapsulated system that has a volume weighted mean particle diameter of from 0.05 to 25 micrometers, at least 25% of the encapsulated particles are spherical and can support its own weight.
EP-A-855177 discloses a whitening powder comprising 0.1 to 7 wt. % trimethylsiloxylated silica having a specific surface area of at least 80 m2/g and a hydrophobicization degree of at least 50%, 5 to 40 wt. % of a polyhydric alcohol, 50 to 94 wt. % water and 0.01 to 5 wt. % of a whitening ingredient.
WO 2005/058256 discloses cosmetic preparations of creme- or paste-like consistency, comprising 50-95 wt. % water, hydrophobized silicon dioxide powder, at least one cosmetically-relevant active ingredient, or adjunct which is water soluble or which may be dispersed or emulsified in an aqueous medium and a viscosity regulator. The above is produced by continuously adding hydrophobized silicon dioxide powder with mixing, to a solution or a dispersion of at least one cosmetically-relevant active ingredient and the mixing is continued until a paste-like consistency is achieved.
Although prior art includes concepts such as the encapsulation of water, the problem with this concept is the amount of additives that could be added while maintaining a stable powder ranged from 0 to 3% by weight depending on additive properties such as the polarity and chain length of the additives. Limiting the formulation to 0 to 3% by weight of an additive, and limiting the additives, reduced the feasibility of the original concept. Even with guidance the industries that have tried using this concept had been unable to overcome the limitations regarding the variety of additives or additive amount.